Neon (Ne)

Neon is the fifth most abundant element in the universe and one of the rarest in the Earth's atmosphere at 18 parts per million, because the young Earth had no way to hold on to a light gas that will not bond to anything. Liquid neon carries about forty times more refrigerating capacity per unit volume than liquid helium, which makes it the practical choice for cooling in the 30 K range. Only true neon glows the familiar red-orange; the other colours in a "neon" sign are argon, mercury vapour or phosphor coatings.

Properties

Atomic number

10

Symbol

Ne

Standard atomic weight

20.18 u

Category

Noble gas

Group

18

Period

2

Block

p-block

Electron configuration

[He] 2s² 2p⁶

Electrons per shell

2, 8

Melting point

24.56 K — -248.6 °C — -415.5 °F

Boiling point

27.07 K — -246.1 °C — -410.9 °F

Density

0.0008999 g/cm³

Oxidation states

0

Discovered

1898 by William Ramsay and Morris Travers

Electron configuration

Full

1s² 2s² 2p⁶

Noble gas shorthand

[He] 2s² 2p⁶

Shells

K: 2 · L: 8

What it is used for

• Neon signs and indicator lamps
• The laser gas in excimer lithography steppers that make computer chips
• Cryogenic refrigerant between 25 K and 40 K
• High-voltage surge arresters and voltage-reference tubes

Density is the gas at 0 °C and 101.325 kPa.

Neighbours in the table

Group 18

Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Neon sits in group 18 with helium, argon, krypton, xenon, radon, oganesson.